London 1753 At the British Museum, Great Russell Street, London WC1, until 23 November
The eminent physician Sir Hans Sloane died in 1753, leaving his library and collections of art, antiquities and specimens of natural history to the nation. The British Museum was born.
An urge to collect and classify knowledge was in the air. Samuel Johnson's Dictionary of the English Language was published in 1755.
Chambers' encyclopaedia had appeared in 1728, to be followed by Britannica in 1768.
The remaining buildings of Georgian London still evoke something of that optimistic era: how else can we get a feel of those times?
The British Museum hit on the idea of celebrating its 250th anniversary by putting on an exhibition focused on London in that great institution's foundation year.
Most of the exhibits are the work of printmakers. They catered for every taste, from the love of art (prints based on paintings by Canaletto, who had arrived in London in 1746) to racism (the Jewish Naturalization Act, giving Jews civil rights, was passed in 1753 and repealed six months later). The drug panic of the time concerned gin:
William Hogarth's celebrated print Gin Lane was published in 1751, and the Gin Act was passed in the same year in an attempt to save the capital from an epidemic of alcoholism.
The largest exhibit is the magnificent 24sheet wall map of London by John Pine and John Rocque, published in 1747. As Ralph Hyde notes in his essay in Sheila O'Connell's indispensable catalogue, Pine and Rocque promised in their proposal to show 'all the Squares, Streets, Courts, and Alleys, in their true Proportions, but likewise of the Ground Plots of the several Churches, Halls, publick Buildings, and considerable Houses and Gardens'.
This was easier said than done. Rocque took bearings of church steeples and trigonometrically computed the proportional distances of various features, but the measurements disagreed with those made with a chain and theodolite on the ground.
The work dragged on for years before the patient subscribers finally had a map to display on their walls. It shows London stretching from Hyde Park in the west - with some new streets in Mayfair marked as being set out - to Deptford in the east, and from Islington in the north to Chelsea and Vauxhall in the south. Lambeth, Kennington and Bermondsey are mainly market gardens.
Samuel Johnson, a native of Lichfield, was famously fond of his adopted city ('when a man is tired of London, he is tired of life').
But he was not blind to its many defects, as his early poem London (1738) testifies. This was a place 'where all are slaves to gold, where looks are merchandise, and smiles are sold'.A large proportion of the people of this wealthy city lived in poverty, many of them resorting to crime and prostitution, as the printmakers - always on the lookout for salacious material to publish - recorded.
'When we deal with cities, ' Jane Jacobs wrote 200 years later, 'we are dealing with life at its most complex and intense.' The new complexity of mid-18th-century London inspired some of its most enterprising citizens to seek to make sense of the city by mapping it, classifying knowledge and cataloguing humankind's most valued artefacts.
But the exploding metropolis was on the verge of becoming incomprehensible.
Dr Johnson had begun his dictionary with the aim of encompassing all human knowledge.He soon found the task beyond even his vast capability, noting in the preface: 'I saw that one inquiry only gave occasion to another that to search was not always to find, and to find was not always to be informed;
and that thus to pursue perfection, was, like the first inhabitants of Arcadia, to chase the sun, which, when they had reached the hill where he seemed to rest, was still beheld at the same distance from them.'
Today, with encyclopaedic knowledge beyond us, the British Museum's well-focused snapshot of a single year is feast enough.
Robert Cowan is director of the Urban Design Group